Drafting instrument.



N0. 819,495. PATENTED MAY 1, 190s. A. A. ALLEN.

DRAPTNG INSTRUISIIENT.

PPLIATI-GH FILED APB. 1905.

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ATTRNEYS UNITED STATES PATENT OFFICE.

RAFTNG INSTRUMENT.

Specification of Letters Patent.

Patented May 1, 1906.

Original application led duly '7,1904,Serisi No. 215.622. Divided andthis application filed April 8, 1905. Serial No. 254,431.

To all whom it may concern:

Be it known that I, ALBERT ARTHUR AL- Y LEN, a citizen of the UnitedStates, and a resident of Ortonville, inthe county of Bigstone and Stateof Minnesota, have invented a new and Improved Drafting Instrument, ofwhich the following is a full, clear, and exact description, this beinga division of the a piication or Letters Patent of the United tetes,Serial No. 215,622, iiled by me July 7, 1904.

The object of the invention is to provide a new and improved draftininstrument, more especiaiiy .designed for t e use of tieners', plumbers,and other mechanics in laying ont the blanks for formin elbows, Ts, andother articles of sheet meta and like VInateriai.

The invention consists of Ynovei features and arts and combinations ofthe saine, Vas will Ve more fully described hereinafter and then pointedout in the claims.

A practical embodiment of the invention is represented in theaccompanying drawings, forming a part of this specication, in whichsimilar characters of reference indicate corres onding parts in all theviews.

igure 1 is a side elevation of the improvement. Fig. 2 is a sectionalplan view of the same on the line 2 2 of Fig. 1, and Fi 3 is atransverse section of the same on the ine 3 3 'of Fig. 1. The dividerA(shown in the accompanying drawings) is arranged for obtaining on thediameter of a tubular body une nelly-spaced diametrical ordinate points.his divider may be used in connection with a peripheral divider of anysuitable or improved construction-such, for instance, as shown anddescribed in the Letters Patent above referred to and arran ed forobtaining ordinate points spaced equa distances apart and dividing theperi hery of a tubular body into equal parts. y drawing from thesepoints it is evident that curved coordinates are ob-V tained to permitof convenientiy and quickly drawing the desired curve.

The divider A is' constructed in detail as follows: A plurality ofspacing-bars C, C', C, and C3 are arranged parallel to each other, thebars C and Cz bein the end bars, the bar C the middle bar, an the bars Cthe intermediate bars, which latter and the middle bar C5 are mounted toslide in bearings D,

ivotally connected With the outer ends of inks or lazy-tongs E,carryingFat the middle of some of the links bearings mounted to slide ona cross-rod G. The middle spacingbar C3 is secured at H to the rod G,while the intermediate bars C have bearingsv H slidabiy engaging the rodG. The end links or lazy-tongs E are connected by pivots I and I' withbearings H2 and H3, slidably en aging the rod G and ri idly carrying theen spacing-bars C and 2. The pivots l and I' are in the form of clampin-screws to allow the o erator to screw up tie ends thereof and c amp thefixed parts in position to heid the divider against movement after thedesired adjustment of the parts is made, as hereinafter more fullydescribed. l'

Y The links or lazy-tongs E are graduated in sizethat is they graduaiiyincrease in size i from the ends toward the middle, as plainly indicatedin Fig. l-the links being so graduated in size that the spacing-bars C,C', and

,C2 stand in such relation to each other that they reduce diametricalordinate points. By a justing the lazy-tongs E so that the points'of theend spacing-bars C" and C2 are a distance apart corresponding to thediameter of the tubular body the spacingbars C and C3, located betweenthe end s seing-bars C and C2, are spaced unequal istances from eachother, and the points marked on the diameter corres ending to the saidintermediate spacing ars are diametrical ordinate points. It isunderstood that lines drawn through the ordinate points at right anglesto thc diameter divide the circumference of the circle for the saiddiameter into equal spaces.

By reference to Figs. 1 and 3 it will be seen that the spacing-bars C,C', C, and G3 are extended beyond the bearings D to form extensions C,which are bent inwardly toward the extension C5 of the middle spacin-bar C3, it being, however, understood that t e said extensions are sobent that the distance between the points at the extension ends will beless than the distance between the points at the other ends of the barsto permit of using the extensions for small diameters the same as theother ends of the spacing-bars, which are used for large diameters.

in order to lav out the blanks for an elbow, for instance, t e operatoropens the lazytongs E so that the distance between the end spacing-barsC and C2 corresponds to the diameter of the tubular body, and then theoperator marks the diametrical ordinate points on the blank sheet of tinor other sheet metal, these points corresponding to the intermediatcspacing-bars. The operator now iigures out the length of the peripheryof the tubs IIO lar body and extends the same at right angles to thediameter laid out on the sheet between the end spacing-bars C and C, as

above explained, and then by means of a suitable peripheral dividerarranged for obtaining ordinate points s aced equal distance a art the oerator divi es the periphery of tlie tubular ody into equal parts andmarks the peripheral points' on the sheet. The coordinate lines are thendra-Wn from both the diametrical and peripheral points, the point ofintersection of the said lines giving the curve coordinate for formingthe necessary curve. The operator now (mis along the line of this curveand then bendsttlie two pieces of the blank into a tubular shape, scthat the two pieces peripherally :[it at :the mite r]oint along thecurved edgesr as will be readily understood.

; For forming Ts and. other .anticles the operator` proceeds insubstaiittiallly the Same manner as above desciribed.

It is understood that the instrument can be readily employed in layingout various 'quickly set the divider other curves required intheformation of tubular jointed bodies. B the use of the device themechanic Lnee s no patterns to be ded by; but he can tto a givendiameter for the purpose above described.

Having thus descril )ed ,my invention, I

Claim as new and desi] re to 'secure by Letters Patent- 1, iininstrument .fol 1 Obtaining curved ooordiiiates, com rising adiameter-divider 35 having Spacingars, a cross-bar mounted o slide inbearings on the 1 said spacing-bars, and connected links slidal iloonnected with the said spacing-bars and e said cross-bar.

2, An instrument i or obtaining curved eoordinates, comprising: adiameter divider having,` s seing-bars, a- Gross-bar mounted toslide inearings 0n ithe said spacing-bars connected links siidsbly Connectedwiih'ih Said Spa@ hars and tliesaid cross-bar, and a 4 5 fastnmg evicefor holding the parts against movement.

3. An instrument for obtaining curved coordinates, epmprising adiameter-divider having spacing-bars arranged parallel and 5o havingreducing extensions at one end, a cross-bar mounted to slide in bearingson the said spacing-bars, and connected links slidabi connected with thesaid spacing-bars an the said cross-bar.

In testimony whereof I have signed my name to this specification in thepresence of twosubscribin Witnesses.

AL ERT ARTHUR ALL EN.

Witnesses:

Trios. F. WILSON,

J. WEBER.

